Recovery of aluminum chloride



vJan. 5 ,1926.

A. MCD. M CAFEE RECOVERY QF ALUMINUM CHLORIDE Filed Jan. 25, 19.22

Patented Jan. 5, 1926s UNITEnsTATES PATENT OFFICE.

ALMEB. MUDUEEIE MCAEEE, b E PORT ARTHUR, TEXAS, AssIeNoE To GULF :REEINING coMPANY, 0E PITTSBURGH, PENNSYLVANIA, A coroEATIoN'oE TEXAS.

RECOVERY QF ALUMINUM CHLORIDE.

Application field January To all lwhom t concern.'

Be it known thatl I, ALMER MCDUFFIE MGAFEE, a citizen of theUnited States, residing at Port Arthur, in the county f 'Jefferson and State of Texas, haveinvented certain new and useful Improvements in the Recovery of Aluminum Chloride, of which the following is a speciication. A

This invention relates to the recovery of aluminum chloride;. and it comprises a method of recovering active aluminum chloride from spent residues containing thc same wherein. such residues are heated to volatilize theV chloride while removing the vapors as fast as formed, either by suction (vacuum) or a currentof gas; all#- as more fully hereinafter'set forth and as claimed.

Aluminum chloride is -a hard crystalline rather volatile body, usually stated to -boil at about 365 F.'but having a lconsiderable vapor tension at temperatures much below this. It is now used in various processes of treating mineral oils wherein its catalytic powers render it valuable. In one such process the mineral oil is heatedwith a small quantity of aluminum chloride, often about v5 per cent, and volatile'oil (gasoline) distilled olf. In another` such process, the aluminum. chloride is warmed with an oil at a comparatively low temperature,-usually about 150J F., -for the pu ose of improving the `character of \the' oi saturatmg -unf saturated compounds, lightening the color, etc( In all these methods 'the aluminum chloride after a certain time loses its activity and forms a' sludge or -what -is known as an as haltic residue or coky `residue from whic the aluminum-chloride must be recovered. When a vbody of hot or warmloil is treated with a ksmall amount of aluminum chloride, say 5 per cent, the chloride combines or melts down with a certain portion of the oil to form a heavy liquid immiscible with the rest 4of the oil. .In the statedmethods, this heavy liquidis kept stirred up through the oil by powerful agitatingl means.' As the operation goes on the eavy` `liquid becomes thicker 'and more viscous until finally it is of asphalt'ic,

tarry, or even coky consistency. Analysis" the" natureloffa sumpl 2 having the. screw -100 25, 1922'. serial No. 531,611.

of these residues shows that the aluminum -chloride is still vpresent in the sense that the residues contain aluminum and chlorine 1n the y( proportion to form AlCh; but the chloride has lost its catalytic activity.

In the usual methods of recovery these residues are heated progressively lto a'high temperature.

oil' and then the hydrocarbons are broken up or coked. Finally the aluminum chloride vaporizes. Vaporization of the alummum chloride maybe` facilitated by the use of a little chlorine. v

- V`I have found that the aluminum chloride, or its hydrocarbon compounds, are sensibly volatlle at temperatures much below those The oil present first distils usually considered necessary in recovery? and that in recovery it is not necessary to brealr up ,or coke the oily bodies present, ii conditions besuch as to maintain a mini- `mum partial preure of aluminum chloride, (or of its compounds with hydrocarbon) in the recovery. This may be d'one either .by the application` of suction (vacuum) or by passing a current of indiierent` as over the residueduring heating. Under these conditions the aluminum chloride and the oil present volatilize, leaving coke and asplialticv hydrocarbons belhind. Y j Operating in 'this manner since I can Work at comparatively lowtemperatures, I not only recoverVV thel aluminum Achloride but `also-a. certain amount of oil which would otherwise be lost. The aluminum chloride andn the oil coming l from the recovery apparatuscondense together,l y

. forming a heavy oilyliquidgwhich maybe methods'of treating oil. l

In `the` accompanyi ng drawings showing `one form of apparatus useful in theperformance .of 'my `process and within the purview of my invention,

'Theil drawing isa diagrammatic sectional vlew. c i

"Referring, toK the drawing, reference numeral `l designates a cooling chamber of i considerable capacity provided at its lower "end'with `a basin or settling chamber in conveyor 3 operated by means outside of the chamber (not shown).y Leading into the chamber at a relatively high point is the conduit 4 provided at a point along its length with a hopper 5 into which the aluminum chloride residueis fed either continuously or from time to time. 4The conduit 4 is heated advantageously at a point beyond the admission of the ,residue by means of the enclosing furnace or lire box 6 provided with oil and gas or other burners 7 and tire exit gas stack 8. `At a point near its lower end this conduit 4 is provided With a line 9y for removal ofrcoke and the like. This line 9 is provided with sealing device 10 which may be in the nature of a pocket valve or the like which is rotated by means extending outside of the line. Coke eliminated is sent to receptacle (not shown). In the conduit 4 vapors of aluminum chloride and hydrocarbon oil pass upwardly into the cooling or capacity cham# ber 1 While gases from the cooling chamber pass by line 11 to pump 12 from whence they\ are circulated through the line 13 back to the conduit 4. If desired additional gases may be admitted to this lineV 13 by the inlet 14, such gases being advantageously inert gases, such as nitrogen and the like. The action however, furnishes its own gases; the operationresulting in the establishment and maintenance of a body of inert gases in cyclic circulation. When there is development ofmexcesslvc gases these may be vented from time to time or continuously through the outlet 15 leading from the cooling chamber suitably valved as at 16.

The operation of the apparatus is as follows: The aluminum chloride residue from gasoline making operation or one of the operations aforesaid, is delivered continuously intothe hopper 5. The furnace 6 supplies the heat to the conduit 4 and the gases therein pass upwardly, which together with the heat extract the aluminum chloride and oil from the residue, which tends to tumble down the inclined conduit 4. The aluminum chloride and oil are separated in the cooling chamber,` and .qondensed. They settle into the sump 2 from which they may be removed by means of the screw conveyor 3. The oil and aluminum. chloride may be tapped ofi' from the sump through the line 17. The gases of this-reaction then pass throughline 11 by means of the pump 12 to the line 13 and back to the conduit 4 being supplemented with other gases through the valved line 14. This pump 12 is not necessary in all cases, Iparticularly wherethe process is run at such a speed or at such a temperature that convection currents are set up.

As has before been stated, the cooling chamber 1 is sealed.

When reliance isnot placed totally upon the use of gases in the process, either those additionally admitted or those resulting from the reaction, the process operates under a vacuum; vacuum pump 18 being tions maintaining a minimal partial pressure of aluminum chloride vapors in the heating apparatus, thereby enabling vol- .atilization of the aluminum chloride Without much destruction of the accompanyling oils.

1. In the simultaneous recovery of aluminum chloride and oil from oily residues containing the same, the process which consists in heating the same to a temperature sutlicient to volatilize the chloride and maintaining a minimal partial pressureof aluminum chloride `vapors in contact with said residue.

2. In the simultaneous recovery of aluminum chloride and oil from oily residues containing the same, the process which conysists in heating the same to a temperature suicient to volatilize Jthe chloride and maintaining a minimal partial pressure of aluminum chloride vapors in cont-act with said residue by passing a current of inert gases over said residue.

3. Inthe recovery ofaluminum chloride and oils from residues containing the same, the process which consists in heating such residue to a temperature sufiicient to volatilize the chloride andl accompanying oils while maintaining a minimal partial' ressure of aluminum chloride vapors an oil vapors in contact with said residue.

' 4. In the recovery of anhydrous aluminum chloride from oily residues containin the same with simultaneous recovery of oi therefrom, the process which consists in heating such residues to a. temperature suficient to volatilize oils and aluminum chloride therefrom, while maintaining a minimal partial pressure of chloride vapors and oil vapors in the space above such resi-` due by passing a current of inert gasesv over the residue being heated.

5. In the simultaneous recovery of alumi` num chloride yand oil from oily residues containing the same, the process which comprises establishing and maintaining a cyclic circulation of inert gases through a cooling chamber and `a heating chamber and su jecting the oily residues containing aluminum chloride to heat` in the lheating chamber in the presence of the circulating gases. 4

6. In the simultaneousy recovery of alumitaining the same, the process which comprises establishing and maintaining a cyclic circulation'of inert gases through a cooling chamber and a heating chamber and subjecting the oily residues containing aluminum chloride to heat in the heating chamber in the presence of the circulating gases,

the temperature being n'suicent to produce com lebe carbonization of the oils in said resi ue.

In testimony whereof, I have hereunto aiixed my signature.

ALMER MGDUFFIE MCAFEE. 

